Top-k Query over Data Management System in P2P Network
P2P环境下数据管理系统上的Top-k查询

Most of existing peer-to-peer (P2P)systems only provide coarsely granular file-level sharing and lack of data management ability. A new framework of database sharing in P2P network is presented, which is based on keyword search over relational databases. In the framework, database on each peer can be seen as a text collection, users needn' t care about the schema information of the database, which greatly simplifies the schema mapping between different peers, and is more suitable for the decentralization and dynamicity of P2P network. Hierarchical top-k query processing algorithm based on histogram is applied in the data management system in P2P network to do top-k query, which uni- fies the query over text collections and relational databases. During the query processing, histogram can be updated au- tomatically by using the returned top-k results, and the neighborhood of the peer can be self reconfigured to let the nodes containing the real top-k results to be its neighbors. Experiment results show that database sharing based on the keyword searching breaks through the traditional database sharing schema and simplifies the data accessing method, and top-k query based on histogram improves the search efficiency.